This invention relates to glass tank furnaces used in the manufacture of glass, and more particularly to a cooperating auxiliary system that recovers heat conducted through the furnace roof or "crown" and uses the recovered heat for preheating some of the combustion air.
Conventional glass tank furnaces tend to operate inefficiently for a number of reasons. Like most furnaces, glass tank furnaces lose heat to the surrounding atmosphere, which heat either should not be lost, or should be recovered in order to improve furnace efficiency. Such heat loss tends to increase as the furnace ages, thereby making it impossible in the first instance to design the furnace for maximum efficiency over the furnace life.
In conventional glass tank furnaces the roof or crown generally is one or the other of two types. One type is the more modern suspended flat arch roof or crown while the other type is the older sprung arch roof or crown. The present invention, as will be seen, improves the efficiency of the glass tank furnaces having both types of roofs or crowns, and also cooperates to prolong the life of furnaces having both types of crowns.